Towards a Neuroscience of Consciousness

What is consciousness? Consciousness is very hard to define, and there are different ways of defining it. But we know some of what consciousness involves. Consciousness is our subjective experience of the world and of being able to taste chocolate, smell roses, and see orange. How does the brain translate sound waves into music and speech? How does it make us experience light waves as colours? Consciousness is being aware of our surroundings and being able to perceive the world and act on our intentions. It is the difference between being under anaesthesia or in a coma and being awake and conscious. 

The question has fascinated humans for centuries. While we have made many discoveries in the realms of evolution and physics, consciousness is still a mystery to us. We haven’t scientifically explored this question until recent years. Descartes first introduced the Mind and Body Problem, wherein there appears to be a world of physical and material objects around us, and another world of thoughts, ideas, imagination, and sensations; since then, we have gotten no closer to understanding how our conscious experiences come about. 

Using several techniques and tools, neuroscientists have now started exploring how the brain works and how it relates to consciousness. One way of studying consciousness is comparing the brain activity of those in an unconscious state and those who aren’t. A study, utilising this method, used transcranial magnetic stimulation to create electrical “echoes” within the brain. Using EEG, after stimulation, the study could detect echoes bouncing around the brain more in someone who was awake. The echoes were much more localised within the brain of someone who was asleep. 

Other studies measure the spontaneous activity of the brain. They’ve found differences in the complexity of brain signals in those who are asleep or under anaesthesia, and those who are awake and conscious. Another interesting finding is that those under the influence of psychedelic drugs show more complexity within their brain signals compared to normal conscious participants. 

Some studies have explored the default mode network and the dorsal attention network. The default mode network is a network of brain regions found when a participant is not involved in any mental task, and their brain activity is measured. Studies associate it with an internal focus on ourselves, using our memory and imagination. On the other hand, studies associate the brain regions of the dorsal attention network with us being aware and engaged with our environment.

We’ve found that both networks have low activity in the brains of the unconscious (anesthetised). These two networks negatively correlate to one another – activity in one of these networks means less activity in the other. Our brains are constantly switching their activity between these two networks. These findings can help us understand how our brains help us interact with the environment, have our own internal world and process the information we get. 

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The findings are interesting because they show us that being intently focused on our internal worlds makes us less engaged with our environment and surroundings. It explains why meditation can help us feel better and more connected to our sensations of the surrounding world. 

These studies help us understand how consciousness can arise and how it correlates with specific brain regions and neural activity. However, this is only a small snippet of the amount of neuroscience research available on consciousness. If you find this topic interesting, I urge you to look into it more since it is fascinating. It has been explored from many perspectives and has a huge implication on our philosophical understanding of who we are and why we are the way we are. 

Some argue that we can never fully understand consciousness, or that consciousness is outside the realm of science; understanding which neurons fire will not explain how these neurons give rise to complex and intense feelings and sensations we have of taste, smell, pain, and sounds. However, we are making progress, and maybe one day we’ll have more tools to understand what our consciousness is and how it came about, better.

Written by Fatma Waleed